Persistent, Bioaccumulative and Toxic chemicals

These substances are Persistent, Bio-accumulative and Toxic (PBT) or very Persistent and very Bio-accumulative (vPvB). These properties correspond to article 57 d-e of REACH.

They do not easily break down in nature. Instead they build up in the environment and in, for example, the fatty tissue of mammals, where they have the potential to cause serious and long-term irreversible effects. Due to their longevity, these chemicals have the potential to cause great harm even at low toxicity, since they can build up and become concentrated over time.

Persistent chemicals can in many cases also be transported to remote parts of the world. Bioaccumulative chemicals that enter the food chain will magnify at each level, leaving top predators – such as whales, eagles, polar bears and ourselves – with the highest concentrations.

The PBT Working Group, an official assembly of representatives from EU member states as well as experts from the former European Chemicals Bureau (ECB), had by 2008 concluded that a number of substances fulfil the EU criteria as PBT or vPvB. These criteria were very similar, although not identical, to those in REACH. These substances were added to the first version of the SIN List, with the exception of substances outside the scope of REACH, such as certain pesticides.

 

Evaluation of PBTs for the 2014 update

Initially, ChemSec screened a number of sources for suspected PBTs, including scientific papers, reports, priority lists from authorities and from organisations. From this gross, comprehensive list, substances already on the SIN List were removed, resulting in more than 1,000 substances.

To narrow down the number of substances, ChemSec considered the use of the substances. Indicated consumer use was defined as substances being present on a selection of product-type related substances lists.

In total, 81 substances were pre-evaluated and 25 substances evaluated in-depth by the scientific team of Professor Martin Scheringer and Dr Carla Aparecida, ETH Zürich during 2013–2014.

Chemicals were investigated for (i) fulfilment of the Annex XIII criteria of REACH as PBT or vPvB substances, (ii) substantial structural similarity to chemicals already regulated under REACH as PBT or vPvB substances or under the Stockholm Convention on persistent organic pollutants, (iii) degradation in the environment or organisms into substances fulfilling (i) or (ii).

After receiving the summaries ChemSec discussed and consulted with a number of experts from authorities, NGOs and research institutes and thereafter selected thirteen substances for this SIN List update. These thirteen substances were identified using a weight-of-evidence approach, considering:

  • Measured data
  • Estimated data
  • Read-across
  • Degradation products
  • Biomonitoring data

 

Evaluation of PBTs for the 2019 update

The assessment process started from the selection of 64 potential persistent, bioaccumulative, and toxic (PBT) substances based on REACH registered chemicals from the list prepared by Strempel et al. (2012). This initial list was expanded by including another 18 potential PBT substances present in several other prioritisation lists.

The expanded list was then reduced in several steps to a final selection of 18 chemicals for which it is likely that they fulfil the PBT/very persistent, very bioaccumulative (vPvB) criteria or an equivalent level of concern and which were then in the main part of the project assessed in detail. The assessments were performed by Professor Martin Scheringer and Dr Helena Andrade from ETH Zurich during 2019.

Chemicals were investigated for (i) fulfilment of the Annex XIII criteria of REACH as PBT or vPvB substances, (ii) substantial structural similarity to chemicals already regulated under REACH as PBT or vPvB substances or under the Stockholm Convention on persistent organic pollutants, (iii) degradation in the environment or organisms into substances that fulfill (i) or (ii).

After receiving the summaries ChemSec discussed and consulted with a number of experts from authorities, NGOs and research institutes and thereafter selected the substances to include in the SIN List. The substances were identified using a weight-of-evidence approach, considering:

  • Measured data
  • Estimated data
  • Read-across
  • Degradation products
  • Biomonitoring data